Just my 2 cents, but with Apex being dev-friendly and all, maybe you can just ask for a twilio API key and just fire the message across?
I've actually been using IFTTT for my PagerDuty replacement since I can't afford it hahaha, unless I'm missing something they don't seem to charge for phone calls etc
Just my 2 cents, but with Apex being dev-friendly and all, maybe you can just ask for a twilio API key and just fire the message across?